Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Microphone Windscreens for Turbulent Noise Suppression when Applying Active Noise Control to Ducts
Responsible organisation
2005 (English)Conference paper, Published paper (Refereed) Published
Abstract [en]

Low noise level is an essential feature when installing ventilation systems nowadays. The traditional noise control approaches use passive silencers to attenuate the undesired ventilation noise. These silencers have a high attenuation over a broad frequency range. However, traditional passive silencers are ineffective at low frequencies and tend to be relatively large and bulky when they are used for low frequencies. An approach to improve the low frequency noise attenuation and to reduce the size of a low frequency silencer is active noise control (ANC). A problem when applying ANC to attenuate noise in ducts is that both the reference microphone and the error microphone are placed in an air flow. Accordingly, the microphones sense the sound propagating through the duct as well as the turbulent fluctuations generated by the wind passing over the microphones. The turbulent flow noise reduces the coherence between the reference microphone and the error microphone, resulting in reduced performance of a feedforward ANC system. For improving the performance it is important with as little corruption from turbulent flow noise as possible. The coherence can be improved by reducing the flow velocity around the microphones by using some kind of windscreen. This paper presents comparison results for microphone installations based on different windscreens for suppression of the turbulent wind noise. The presented measurements are carried out in the frequency range 0-400 Hz - the plane wave propagation region for the ducts in use - and for flow speeds up to 5,9 m/s. The results show that with appropriate screens and placement the attenuation and frequency range of attenuation can be significantly improved.

Place, publisher, year, edition, pages
Lisbon, Portugal: International Institute of Acoustics and Vibration , 2005.
Keyword [en]
active noise control, ventilation systems, duct, microphone windscreen
National Category
Signal Processing
Identifiers
URN: urn:nbn:se:bth-9585Local ID: oai:bth.se:forskinfoC0AA413C9C5E338FC125706E007113C7OAI: oai:DiVA.org:bth-9585DiVA: diva2:837469
Conference
Twelfth International Congress on Sound and Vibration, ICSV12
Available from: 2012-09-18 Created: 2005-08-31 Last updated: 2015-06-30Bibliographically approved

Open Access in DiVA

fulltext(577 kB)119 downloads
File information
File name FULLTEXT01.pdfFile size 577 kBChecksum SHA-512
03110b4dd62ae574f6cc263cfead4b2fef120b87faa09c7cb20f7bb8d83f95bd997e739d658286ee59273bb642cd90bf0eaa981f68d62c6f11bfd6a947c5e4f2
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Johansson, SvenHåkansson, LarsClaesson, Ingvar
Signal Processing

Search outside of DiVA

GoogleGoogle Scholar
Total: 119 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 86 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf